Fire extinguishing system



H. V. WILLIAMSON ET AL FIRE EXTINGUISHING SYSTEM 7 Sheets-Sheet 1 Filed March 4, 1954 HHIH ' Filed March 4, 1954 1956 H. 9. WILLIAMSON ET AL 2,758,657

FIRE EXTINGUISHING SYSTEM 7 Sheets-Sheet 2 Aug. 14, 1956 v, w mso ETAL 2,758,657

FIRE EXTINGUISHING SYSTEM Filed March 4, 1954 v 7 Sheets-Sheet 5 Aug. 14, 1956 v, wlLLlAMSON ETAL 2,758,657

FIRE EXTINGUISHING SYSTEM Filed March 4, 1 954 7 Sheets-Sheet 5 g- 1956 H. v. WILLIAMSON ETAL 2,758,657

FIRE EXTINGUISHIN' G SYSTEM 7 Sheets-Sheet 6 Filed March 4, 1954 "a? 1 I 1/474 EIZM M IWE Aug. 14, 1956 H. v, w s0 ET AL 2,758,657

FIRE EXTINGUISHING SYSTEM 7 Sheets-Sheet 7 Filed March 4, 1954 United States Patent EXTINGUISHING SYSTEM Hilding V. Williamson, Chicago, and Alan D. Conner,

Homewood, IlL, assignors to Cardox Corporation, Chicago, 111., a corporation of Illinois Application March 4, 1954, Serial No. 414,126

15 Claims. (Cl. 169-9) This invention relates to new and useful improvements in fire extinguishing systems and deals more particularly with systems in which the discharge of the fire extinguishing medium is delayed for a predetermined time interval after the system is actuated and the discharge of the medium is continued for a period of predetermined duration.

Fixed fire extinguishing systems employing an extinguishing medium such as carbon dioxide are frequently used to protect enclosed hazards in which personnel are working or are apt to be located. In such instances, it is important that the endangered personnel be given suflicient time to vacate the hazard before it is flooded with the inert extinguishing medium. For this reason, many fixed fire extinguishing systems include a delay mechanism that initiates the actual discharge of the extinguishing medium a sufficient length of time after the system has been placed in operation so that the personnel in the hazard will have time to depart therefrom.

Prior fire extinguishing systems employing an expendable supply of extinguishing medium, such as carbon dioxide, usually include mechanisms of various types for controlling the length of time the extinguishing medium is discharged into any one hazard so that the limited supply will be sufficient to extinguish fires in several hazards.

The discharge delay and timing mechanisms of certain prior known types have been dependent for their operation upon a source of electrical power that, for one reason or another, may have failed at the time a fire occurs. In other instances, the devices have required constant care and maintenance to ensure their proper operation, and, therefore, have been subject to substantial variations and delay in timing function.

It is the primary object of this invention to provide a fire extinguishing system with which the discharge of the extinguishing medium is automatically delayed for a predetermined time interval after the system is placed in operation and the delaying operation is independent of any pOWer source apart from that supplied by the system.

A further important object of the invention is to provide a fire extinguishing system which provides an accurately controlled delay period after the system is actuated and before the discharge of the extinguishing medium starts and during which period a warning may be given so that any personnel within the hazard will have time to depart.

Another object of the invention is to provide a non electrical actuating and control mechanism for fire extinguishing systems which will both initiate the discharge of the extinguishing medium and will discontinue the discharge after the elapse of a predetermined period of time.

Still another object of the invention is to provide an actuating and control device for fire extinguishing systems which can be set into operation at a hazard protected by the system or at a point remote therefrom and which, after it has been set into operation, receives its motivating power entirely from the pressure of the extinguishing medium used in the system.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like reference characters are employed to designate like parts throughout the same,

Figure 1 is a front elevational view of an actuating and control mechanism embodying the invention,

Figure 2 is a horizontal sectional view taken on line 2-2 of Fig. 1,

Figure 3 is a vertical sectional view taken on line 3--3 of Fig. 1,

Figure 4 is a top plan view, partly broken away, of the valve assembly for controlling the length of the delay interval,

Figure 5 is a vertical sectional view taken on line 55 of Fig. 4,

Figure 6 is a vertical sectional view taken on line 66 of Fig. 4,

Figure 7 is a top plan view, partly broken away, of the pilot valve assembly for controlling the length of the discharge period,

Figure 8 is a vertical sectional view taken on line 8-8 of Fig. 7,

Figure 9 is a vertical sectional view taken on line 99 of Fig. 7,

Figure 10 is a fragmentary vertical sectional view taken on line 1tl-1t) of Fig. 7,

Figure 11 is a horizontal sectional view taken on line ill-11 of Fig. 8,

Figure 12 is a front elevational view, partly broken away, of the actuating valve employed in the invention,

Figure 13 is a vertical sectional View taken on line 13-13 of Fig. 12,

Figure 14 is a horizontal sectional view taken on line 1414 of Fig. 12,

Figure 15 is a horizontal sectional view taken on line 1515 of Fig. 12,

Figure 16 is a diagrammatic view of the device illustrated in Fig. 1, connected to a second, remotely located actuating valve, and

Figure 17 is a diagrammatic view of a fire extinguishing system embodying the invention.

In the drawings, wherein for the purpose of illustration are shown the preferred embodiments of this invention, and first particularly referring to Figs. 1 to 3, inclusive, reference number 18 designates an actuating and control device in its entirety, the same being housed in a box 19 having a recessed front panel 20 and provided with a mounting bracket 21 on the inner face of its rear wall. The recessed front panel 20 is removably mounted in the control box 19 by screws 22 to permit access to the interior of the box.

Mounted within the control box 19 on the mounting bracket 21 are a pilot valve assembly 23, an actuating valve 24 and a control valve assembly 25. The actuating valve 24 is operated by rotation of a rod 26 which extends outwardly through the bushed opening 27 in the recessed front panel 20, and is provided with an operating handle 28 by means of which the rod 26 can be manually rotated.

A carbon dioxide vapor supply duct 29 is connected through a coupling device 31 to a pair of branch ducts 32 and 33 which supply carbon dioxide vapor under pressure to the inlet ports of the pilot valve assembly 23 and the actuating valve 24, respectively. The outlet port of the pilot valve assembly 23 is connected to a point of use, as will be later described, by a duct 34 having a coupling device 35 therein at one side of the control box 19. The outlet port of the actuating valve 24 is connected to the inlet port of the control valve assembly 25 by a duct 36 and the exhaust port of the actuating valve has a duct 37 connected thereto which includes a coupling device 38 at the side of the control box 19 for a purpose that will be later described. A duct 39 extends between and connects the supply port of the operating and timing portion of the pilot valve assembly 23 and the outlet port of the control valve assembly 25. The control Valve assembly is also provided with a by-pass port that is always in open communication with its inlet port and is connected to a duct 41 which extends through a coupling device 42 at the side of the control box 19 for a purpose that will be later described.

Referring now to Figs. 7 to 11, inclusive, for a detail description of the pilot valve assembly 23, the body 43 of the valve is formed with an inlet chamber 44, an exhaust chamber 45 and an outlet chamber 46 that is positioned between the inlet and exhaust chambers. The inlet chamber 44 is connected through the inlet port 47 to the branch 32 of the carbon dioxide vapor supply duct 29. An exhaust port 48 provides open communication between the exhaust chamber 45 and the atmosphere and an outlet port 49 provides communication between the outlet chamber 46 and the duct 34. The outer end opening of the inlet chamber 44 is closed by the plug 50 that is threaded into the body 43 of the valve and is provided with a cylindrical recess 51 in its inner end portion.

Positioned in the inlet chamber 44 is a piston type valve 52 having a guide portion 53 which loosely fits the bore of the chamber to guide the movement of the valve. Opposite ends of the guide portion 53 are in open communication with each other through the clearance space between the bore of the chamber 44- 'and the outer surface of the guide portion to permit free movement of the valve 52 in the chamber 44. A cylindrical recess 54 is formed in the end of the guide portion 53 in axial alignment with the recess 51 in the plug 56 and a spring 55 is positioned with its opposite ends in the recesses 51 and 54 to urge the valve 52 toward its closed position.

Between the guide portion 53 of the valve 52 and the adjacent end of the outlet chamber 46, the valve is reduced in diameter and has mounted thereon a sealing gasket 56 that is clamped against the reduced portion of the valve by the enlarged head of the screw 57 that is threaded into the valve. The head of the screw 57 is adapted to seat in the rabbeted end 58 of the outlet chamber 46 so that the sealing gasket 56 can seat against the end wall 59 of the inlet chamber 44 to seal between the inlet and outlet chambers.

The chambered pilot valve operating and timing device .62 is mounted on the valve body 43 adjacent the exhaust chamber 45 by means of a connector 63 which is threaded into the outer end of the exhaust chamber. The inner end of the connector 63 is provided with an enlarged bore 64 into which is loosely fitted a plunger 65 with a suificient clearance to permit the passage of gases. The plunger 65 has formed therein an upwardly opening chamber 66 in which is positioned a compressed spring 67 that is retained in place by a plug 68. The inner end of the plunger 65 has mounted thereon a sealing washer 69 that is clamped against the end of the plunger by the collar 70 of the operating rod '71 which is threaded into the end wall of the plunger and extends into operating engagement with the head of the screw 57. The washer 69 is movable when the plunger is moved inwardly to place the washer in engagement with the shoulder 72 at the adjacent end of the outlet chamber 46 and to provide sealing between the outlet and exhaust chambers. Inward movement of the plunger 65 will also cause the operating rod 71 to move the valve 52 into its open position.

The pilot valve operating and timing device 62 is rigidly clamped in sealing engagement with the top of the body 43 by the head of the threaded connector 63. The chambered interior of the device 62 is divided into an inner portion 73 and an outer portion 74 by a flexible diaphragm 75. A disc '76 is positioned adjacent the diaphragm 75 in the inner portion 73 of the chamber and is provided with a pin 77 that extends from the disc through the outer end of the threaded connector 63 for engagement with the spring retaining plug 68 of the plunger 65. Suflicient clearance is provided between the outer surface of the pin 77 and the end bore of the con nector 63 to permit restricted passage of gases therethrough. Fastened above the diaphragm 65 is a perforated disc 78 for engaging the diaphragm to prevent excessive upward movement thereof.

When the disc 76 is moved by the diaphragm 75 in a direction to depress the pin 77, the engagement between the pin and the spring retaining plug 68 will cause the plunger 65 to move the washer 69 into sealing engagement with the shoulder 72. Further movement, or overtravel, of the pin 77 is made possible by movement of the retaining plug 68 to further compress the spring 67 to thereby prevent damage to the washer 69. It will be readily apparent that the spring 67 must be of sufficient strength to insure positive sealing engagement between the Washer 69 and the shoulder 72 against the maximum force exerted by the pressure of the gas in the chamber 46.

The inner portion 73 of the chambered interior of the device 62 is in communication with the duct 39 through the supply port 79. The inner and outer portions 73 and 74 of the chambered interior of the device 62 are in communication with each other through passageways 81 and 82 and the valve chamber 83 in the wall of the device. A ball check valve 84 is provided in the chamber 83 and is urged into its seated position against the O-ring 85 by a spring 86 to permit the unidirectional flow of gases from the inner portion 73 to the outer portion 74.

Venting of the outer portion 74 of the chambered interior of the device 62 is provided by a venting valve 87 and by a venting plug 88 having a shouldered passageway 89 therethrough into which are fitted a plurality of. discs 91 which may be formed of porous stainless steel, or the like. The porous discs 91 permit the continuous restricted flow of gas through the passageway 89 in the plug88 and the venting valve 87 permits relatively rapid venting until the pressure in the outer portion 74 of the chambered interior of the device 62 is increased to a value sufficiently high to effect closing of the valve, after which the venting valve will remain closed until the pressure in the outer portion is reduced to a predetermined value.

The venting valve 87 is formed with a passageway 92 having an enlarged portion into which a ball check valve 93 is inserted with sufficient clearance between the ball and the enlarged passageway to permit the limited flow of gas therethrough. At the outer end of the enlarged portion of the passageway 92 a valve seat 96 is provided by the chambered cap 95 and an O-ring 96 is positioned adjacent the seat to provide sealing between the ball valve 93 and its seat. Gases flowing past the ball valve 93 in the enlarged portion of the passageway 92 are released from the valve through the port 97. Positioned in the chambered interior of the cap 95 is a plunger 93 which is urged by the spring 99 into engagement with the ball valve 93 to move the ball away from its seated position. The outer end of the spring 99 bears against an adjusting screw 100 which is threaded into the outer end of the cap 95 to vary the pressure exerted by the spring against the plunger 98 and the ball valve 93. In other Words, the position of the adjusting screw 1% may be changed to vary the value of pressure to which the gas in the outer portion 74 of the chambered interior of the device 62 must be reduced, after the valve has been closed, before the spring 99 will move the ball valve 93 into its open position.

Referring now to Figs. 12 to 15, inclusive, for a detail description of the actuating valve 24, the valve body 101 is provided with an elongated passageway therethrough having an enlarged upper end portion to provide an inlet chamber 102 and an enlarged lower end portion to provide an exhaust chamber 103. The reduced portion of the passageway between the chambers 102 and 103 forms an outlet chamber 104. A plug 105, having a cylindrical recess 106 in its inner end, is threaded into the valve body 101 to close the outer end of the inlet chamber 102. An inlet port 107 provides communication between the inlet chamber 102 and the branch 33 of the carbon dioxide vapor supply duct 29 and communication is provided between the exhaust chamber 103 and the duct 37 by an exhaust port 108. An outlet port 109 extends from the outlet chamber 104 to provide communication between said chamber and the duct 36.

A piston type valve 110, having a recess 111 in its outer end, is loosely fitted in the bore of the inlet chamber 102 to permit the flow of gas thereby to equalize the pressures on opposite sides of the valve. A sealing washer 112 is clamped between the inner end of the valve 110 and the head of the screw 113 and a spring 114 is positioned with its opposite ends in the recesses 106 and 111 and is compressed between the plug and valve to urge the washer into sealing engagement with the end wall 115 of the inlet chamber 112. A second piston type valve 116 is fitted into the bore of the exhaust chamber 103 and projects outwardly from the end of the valve body 101. Sealing is provided between the valve 116 and the bore of the exhaust chamber 103 by an O-ring 117 which is positioned in the groove 118 in the periphery of the valve. A washer 119 is clamped against the inner end of the valve 116 by the operating rod 120 which is threadedly connected to the valve and extends through the outlet chamber 104 into operating engagement with the screw 113. The washer 119 is movable into and out of sealing engagement with the end wall 120a of the exhaust chamber 103 to seal between the exhaust and outlet chambers. It will be noted that when the washer 112 is seated against the end wall 115, the outlet chamber 104 is in open communication with the exhaust chamber 103 and the exhaust port 108, and when the valve 116 is moved upwardly to eifect engagement between the washer 119 and the end wall 120a of the exhaust chamber 103, the inlet chamber 102 and outlet chamber 104 are in open communication with each other and communication between the exhaust chamber 103 and the outlet chamber 104 is closed.

Mounted on one end of the valve body 101 are a pair of slide rods 121 having a block 122 mounted for longitudinal movement thereon. The block 122 is urged toward the valve body 101 by springs 123 which are compressed between the block and nuts 124 threaded onto the outer ends of the rods 121. The valve operating rod 26 is journaled in the block 122 for rotary movement between positions at which the radial pin 125 of the rod engages the stop pins 126 which project outwardly from the back of the block. A cam 127 is mounted on the rod 2-6 for rotation therewith when the rod is operated by its handle 28. The cam 127 is formed with an eccentric cumming surface 128 which engages the projecting end of the valve 116 so that rotation of the cam will cause the valve 116 to ride upwardly on the camming surface when the handle 28 is turned in a direction to close the valve 116 and open the valve 110 and will ride downwardly to open the valve 116 and close the valve 110 when the handle is rotated in the opposite direction. Movement of the block 122 against the pressure of the springs 123 will prevent damage to the washers 112 and 119 due to an excessive pressure exerted by the cam 127.

Referring now to Figs. 4 to 6, inclusive, for a detail description of the control valve assembly 25, the inlet port 129 of the valve is in communication with the outlet port of the actuating valve 26 through the duct 36. A passageway 131 connects the inlet port 129 to an inlet chamber 132 that is formed in the valve adjacent its outlet chamber 133. An outlet port 134 provides com munication between the outlet chamber 133 and the duct 39 and a by-pass port 135 is formed in the same manner as the inlet port 129 and is always in open communication with the latter port through the inlet chamber 132. The upper portion of the control valve assembly 25 is formed with a control chamber 136 therein that is separated from the inlet chamber 132 by a flexible diaphragm 137.

A piston type valve 138 is positioned in the inlet chamber 132 and is provided with a washer 139 that is clamped between the valve and the head of the screw 140 and adapted to seat against the shoulder 141 to seal between the inlet and outlet chambers 132 and 133, respectively. Sufi'icient clearance is provided between the screw 140 and the bore of the chamber 133 to permit the free flow of gas from the inlet chamber 132 to the outlet port 134 when the valve is open. The valve 138 is provided with a threaded extension 142 which projects through a central opening in the diaphragm 137 and is threaded into the disc 143 to clamp the diaphragm therebetween. A spring guide 144 projects from the disc 143 into spaced relationship with the upper portion of the pilot valve assembly 25 to limit movement of the diaphragm in an upward direction and a spring 145 is placed over the guide 144 and compressed between the disc and the upper portion of the control valve assembly to urge the disc and the attached valve 138 in a direction to cause the washer 139 to be seated against the shoulder 141.. The head of the screw 140 engages the end wall of the chamber 133 to limit movement of the valve in a downward direction and to prevent damage to the washer 139 when the valve is closed. The head of the screw 140 also serves as a guide to assure proper seating of the washer 139 against the shoulder 141.

An annular groove 146 is formed adjacent the inner face of the diaphragm 137 and communicates with the inlet port 129 through a passageway 147. Restricted communication between the groove 146 and the control chamber 136 is provided by passageways 148, 149 and 151 formed in the body of the control valve assembly 25 and through the groove 152, radial passageways 153 and axial passageway 154 in the control plug 155. A plurality of discs 156 formed of porous stainless steel, or the like, are positioned in the passageway 154 to restrict the flow of gases into the control chamber 136 and sealing is provided between the groove 152 and the exterior of the control valve assembly 25 by a gasket 157 and between the groove and the control chamber by an O-ring 158.

Referring now to Fig. 16 for a detail description of the installation and operation of the above described actuating and timing device 18, it will be seen that the two branches 32 and 33 of the carbon dioxide vapor supply duct 29 are connected to the inlet ports 47 and 107 of the pilot control valve 23 and actuating valve 24, respectively. Under normal conditions, therefore, the inlet chamber 44 of the pilot control valve assembly 23 is filled with carbon dioxide vapor at supply pressure so that the sealing gasket 56 is urged into sealing engagement with the shoulder 59 by the combined forces exerted by the gas pressure and the spring 55 to prevent the fiow of gas into the outlet chamber 46. The sealing washer 112 in the inlet chamber 102 of the actuating valve 24 is similarly urged against the end wall 115 by the pressure of the carbon dioxide vapor in the inlet chamber 102 and the force of the spring 114 to prevent the flow of vapor to the outlet port 109 of the actuating valve. At this time the outlet port 49 of the pilot control valve assembly 23 is in open communication with the exhaust port 48 to provide atmospheric pressure in the duct 34.

When it becomes desirable that pressure fluid be admitted to the duct 34, as will be later described, the handle 28 of the actuating valve is rotated clockwise to eflect rotation of. the cam 127 and to cause movement of the pistont-ype valves 110- and 116- topositions at which the' washer'119 'is sea-ted against the end wall 120a to- Carbon dioxide vapor under pressure will then flow into the duct 36- from the outlet port 109 of the actuating valve and into the inlet port 129 of the control valve assembly Since the by-pass port 1'35 of the control valve. 25 is in open communication with the inlet port 129', carbon dioxide vapor will also flow into the duct 4.1 for: use in operating a: pressure responsive device, as will be. later described.

When. carbon dioxide vapor under pressure flows to the inlet port 129- of the control valve assembly 25, the valve member 139 islifted from the shoulder 141 by the force exertedby the vapor on the diaphragm 137. This movement of: the valve member 139 will cause the spring 145 who compressed. and will move the spring guide 144into engagement with the upper portion of the controlvalve assembly 25'. At this time the outlet port 134 is in; open. communication with the inlet port 129' and carbon dioxide vapor will flow from the outlet port into the duct 39. During the above described opening of the valve 139-, carbon dioxide vapor will also flow from the inlet port 129 to the control plug 155 and through the porous. discs 156 into the control chamber 136 at a predetermined retarded rate: depending upon the porosity and number of the discs 156; After the valve member 139 has been moved to open the outlet port 134 for a predetermined period of time, the vapor flowing through the porous discs 156 will cause an increase in pressure in the control chamber 136 to a value at which the force exerted on the disc 143 and the adjacent side of the diaphragm 137 combined with the spring force will move the valve to its closed position. Closing of the valve 139, of course, will prevent further flow of carbon dioxide vapor through the outlet port 134 into the duct 39 and it Willbe readily apparent that the valve 139 will remain in its closed position. for so long as the combined forces exerted by the pressure of the gas in the control chamher 136 andthe spring 135 cxceedthe force exerted by the pressure of the. gas in the inlet chamber on the diaphragm 137.

Considering now the function of the. pilot valve operating: and timing device 62,. when carbon dioxide vapor is. permitted to flow through the duct 39; the vapor enters the supply port 79" and flows into the inner portion 73 of the chambered interior of the device. The relatively rapid' increase of the pressure within the inner portion 73' willmove the ball. check valve 84 into its open position. permitting the vapor to flow from the inner portion 73 to the outer portion 74 and tending to equalize the pressures inboth portions of the chambered interior of the. device 62. The increase in pressure in the outer portion74 will urge the ball 93 of the venting valve 87 into-sealing engagement with its seat 94 and the O-ring 96;t0 prevent the escape of gas through the valve after the pressure has been increased to a value at which the forceexerted. thereby on the ball 93 exceeds the force applied to; the ball by the spring; 99; During this chargingofithe inner and outer portions 73 and 74, respectively, there is a continuous venting of gases from the inner portion 73 through the clearance space around the pin- 77 and plunger 65 to the exhaust port 48' of the pilot valve and gases are also vented from the outer portion.74-throughthev porous. discs 91 in the vcnting'plug 88 at a retarded" rate relative. to the ventingof the gases from they inner portion 73. When, therefore, the flow of gases through the duct 39 is stopped by the closing of the valve 139 after a predetermined period of time, the pressure in. the inner portion 73 is quickly vented through the exhaust port 48 of the pilot valve and the pressure, in the outer portion 74. will act upon the diaphragm" 75' to move the pin 77 in a downward direction: This movement of the pin" 77 "will cause it'to en gage the spring: retaining plug" 68' of the plunger to its seated position against the shoulder 59 so that the inlet port 47 is inopen communication with the outlet port 49 and carbon dioxide vapor will flow from the outlet port into the duct 34.

The continuous retarded venting of carbon dioxide vapor from the outer portion 74 of the chambered interior of the. device 62 through the porous discs 91 in:

. the venting plug. 88 will gradually reduce the pressure in the outer portion so: that: after a predetermined period of time the ball 93 of the venting valve 87 will be moved to its open position by the spring 99 and the remaining pressure in the outer portion will be quickly vented through the venting valve. The sealing gasket 56 will thereupon be returned to'its seated position by the pressure of the spring 55- against the valve 52 and by the pressure of the gas in the inlet chamber 44 acting on the gasket 56.v The return of the gasket 56 to its seated position will permit the pressure in the duct 34' to be vented through the exhaust port 48 of the pilot valve. The time interval during which the gasket 56 is held in it's open position may be varied by changing the number or porosity of the discs 91 and by varying the degree to which the spring 99 in the venting valve 87 is compressed by the adjusting screw 100. For example, the compression of the spring 99' may be varied to cause the ball 93* to move to its open position when the pressure in the outer portion 74 of the chambered interior of the device 62 lies atany value from 20 to pounds Per square inch.

It will be readily apparent that the rate at which gases are vented through the. porous discs 91 will increase as the pressure of the gases increases so that a slight variation. in the maximum pressure of the gases in the outer portion 74 will have little effect upon the time interval during which the gasket 56 is held in its open position by the pressure acting on the diaphragm 75. Further, theminimum value of the pressure in the outer portion 74 will be maintained substantially constant by the proper adjustment of the screw 100 of the venting. valve 87 so that reclosing of the valve 55 will not be affected by variations in the maximum pressure in the outlet chamber 46.

To summarize the above described operation of the actuating and control device 18, the handle 28 of the actuating valve 24 is moved to the open position to initiate the actuating and control functions. The operation of the handle 28 will cause the actuating valve 24 to be opened to permit carbon dioxide vapor to flow to the. control valve assembly 25 and to open the control valve 139 so that a charge of vapor is introduced to the inner and outer portions 73 and 74, respectively, of the chambered interior of the pilot valve operating and timing. device 62. Thecontrol valve 25 is subsequently closed, after the lapse of a predetermined time interval, by the pressure of the vapor in the control chamber 136 which is gradually increased.

Immediately after the control valve is closed to stop the flow of carbon dioxide through the duct 39, the inner portion 73 of the chambered device 62 is quickly vented to reduce the pressure therein while the pressure in the outer portion 74 remains at a relatively high value. This d-iflerential in. the pressures in the inner and outer portions 73 and 74 will effect opening of the pilot valve gasket 56. to permit carbon dioxide vapor to How to the duct 34. The pressure in the outer portion 74 is thereafter reduced at a restricted. rate through the porous discs 91' to a value at which the venting. valve 87 opens and quickly vents the. remaining. pressure from the outer portion so that the pilot valve will return to its closed position to stop the flow of carbon dioxide to the duct 34 and to vent the pressure from the duct.

For so long as the actuating valve 24 remains in its open position, there can be no further flow of carbon dioxide vapor into the duct 34. Return of the actuating valve 24 to its closed position, however, will permit the pressure in the control chamber 136 of the control valve assembly 25 to be vented through the porous discs 156 and the inlet port 129 into the duct 36 and through the exhaust port 108 of the actuating valve so that, after a very short interval of time, the actuating valve can again be opened to repeat the above described cycle.

As illustrated in Fig. 16, a second actuating valve 159, which is identical to the actuating valve 24, may be located at a point that is remote from the actuating and timing device 18. When so located, the inlet port 167 of the valve 159 is connected to a source of carbon dioxide vapor supply by a duct 161 and the outlet port 109 is connected to the exhaust port 108 of the actuating valve 24 by the duct 37. Operation of the handle 28 of the valve 159 will initiate operation of the actuating and timing device 18 in the following manner:

Carbon dioxide vapor will flow through the duct 161 to the outlet port 189 of the valve 159 when the valve is open and will thereafter flow through the duct 37 into the exhaust port 188 of the actuating valve 24 which is in open communication with the duct 36. Opening of the valve 159, therefore, will supply carbon dioxide vapor to the duct 36 in the same manner as would the opening of the actuating valve 24. Further, the exhaust port 108 of the valve 24 is in open communication with the atmosphere for so long as the valve 159 is in its closed position so that the provision of the second valve 159 will have no effect on the operation of the valve 24 to actuate the system as previously described.

Referring now to Fig. 17 for a detail description of the manner in which the above described actuating and timing device 18 may be utilized to control the operation of a carbon dioxide fire extinguishing system, a tank 162 is provided for maintaining a supply of liquid carbon dioxide stored under its own vapor pressure and at a con stant low temperature available as a fire extinguishing medium. A dip tube 163 extends into the liquid space within the tank 162 and is connected to a header 164 having branches 165, 166 and 167 which extend to hazards A, B and C, respectively. A piston operated master valve 168 controls the flow of carbon dioxide from the storage tank into the header 164 and the admission of carbon dioxide to the piston of the master valve through the branch duct 169 is controlled by a conventional pressure fluid operated pilot valve 171.

The branches 165, 166 and 167, leading from the header 164 to the various hazards, are provided with conventional pressure fluid operated selector valves 172, 173 and 174, respectively. Operation of the system, therefore, to extinguish a fire in any one of the hazards A, B or C requires the opening of the master valve 168 and the selector valve 172, 173 or 174 which is associated with the particular hazard in which the fire occurs.

Connected to the vapor space of the storage tank 162 is a carbon dioxide supply header 175 having branches 176, 177 and 178 connected to the actuating and timing devices 179, 181 and 182, respectively. Each of the devices 179, 181 and 182 is identical to the previously described actuating and timing device 18 but the manner in which each is connected into the system varies and will be described in detail as follows:

Considering first the device 179, it is to be located in or adjacent to the hazard A for actuating and controlling the discharge of the fire extinguishing medium into this hazard. The duct 34, therefore, is connected to the selector valve 172 so that the flow of carbon dioxide vapors through the duct 34 will effect opening of the selector valve and venting of the duct 34 will elfect closing of the selector valve. The carbon dioxide vapor 10 supply duct 29 is connected to the branch 176 of the vapor supply header 175.

The device 179 is provided with a second actuating valve, as described in connection with Fig. 16, located at a station 183 that is remote from the hazard A. The second actuating valve has its inlet port connected to the branch 176 of the vapor supply header 1.75 by the duct 161 and its outlet port connected to the exhaust port of the actuating valve of the device 179 by the duct 37. The duct 41 of the device 179 is connected through a conventional type shuttle valve 184 and a duct 185 to the pilot valve 171 for the branch duct 169 of the master valve 168. The shuttle valve 184 is of the type which incorporates a sliding valve member that is movable by the pressure at either of two inlets to close the other inlet and to permit flow of vapor from the inlet which remains open to the outlet of the valve.

When a fire is discovered in the hazard A, the device 179 is set in operation by opening the actuating valve either at the device or at the remote station 183, as described in connection with Fig. 16. Carbon dioxide vapors will thereupon flow through the duct 41, the shuttle valve 184 and the duct 185 to the pilot valve 171 to etfect opening of the branch duct 169. When the duct 169 is opened, the master valve 168 will be opened to flood the liquid header 164 and each of its branches 165, 166 and 167. After a predetermined time interval, during which the pilot valve assembly receives its charge of carbon dioxide vapors, the control valve of the device 179 will close to effect opening of the pilot valve so that carbon dioxide vapor will flow through the duct 34 to the piston operated selector valve 172 to open the latter. Liquid carbon dioxide will thereupon flow through the branch of the header 164 and be released into the hazard A for a predetermined period of time during which suflicient carbon dioxide is discharged to effect extinguishment of the fire. The pilot valve of the device 179 is then returned to its closed position to vent the duct 34 and close the selector valve 172. This discharge of liquid carbon dioxide into the hazard A is thereby discontinued and the device 179 is reset for subsequent operations by reclosing the previously opened actuating valve which will vent the control chamber of the control valve in the device 179 and the ducts 41 and 185 to close the pilot valve 171 and the master valve 168.

Considering now the device 181 and the manner in which it functions to actuate and control the discharge of carbon dioxide into the hazard B, it will be noted that the duct 34 of this device is connected to the selector valve 173 so that the selector valve will be opened when carbon dioxide vapors flow through the duct 34 and will be closed when this duct is vented. The vapor supply duct 29 of the device 181 is connected to the branch 177 of the vapor supply header and the duct 41 is connected to a shuttle valve 184a, of the previously described type, and to a pilot valve 186 which controls the flow of carbon dioxide from the branch 166 of the liquid header 164 to a whistle 187, or the like, through the duct 188..

When a fire is discovered in the hazard B, the device 181 is set in operation by opening its actuating valve at which time carbon dioxide vapors will flow through the duct 41, the shuttle valve 184av and a duct 189 to the shuttle valve 184. This flow of carbon dioxide vapors through the duct 189 will cause the shuttle valve 184 to close the duct 41 from the device 179 so that the carbon dioxide vapors will fiow through the shuttle valve 184 into the duct and to the pilot valve 171 in the branch duct 169 to open the latter valve. The master valve 168 will thereupon be opened to fill the liquid header 164 and each of its branches 165, 166 and 167. Carbon dioxide vapors will also flow through the duct 41 into the duct 191 to open the pilot valve 186 and permit carbon dioxide to flow through the duct 188 to the whistle 187 which will sound an alarm so that personnel within the hazard. B may depart or be evacuated there-- from. After the master valve 168 has been opened and the alarm 187 has sounded for a predetermined period of time during which the pilot valve assembly 23 of the device 181 receives its charge of carbon dioxide vapors, the control valve of the device will close to effect opening of the pilot valve so that carbon dioxide vapor will flow through the duct 34 and will cause the selector valve 173 to open and permit discharge of carbon dioxide into the hazard B. This discharge of carbon dioxide into the hazard B will continue for a predetermined period of time which is sufiicient to flood the hazard B and will be stopped by the movement of the pilot valve of the device 181 to its closed position at which time the duct 34 is vented through the exhaust port of the pilot valve. The device 181 is reset for subsequent operations by returning its actuating valve to its closed position to vent the duct 41 and to thereby effect closing of the pilot valves 186 and 171 so that the master valve will be returned to its closed position and the alarm 187 will cease to operate.

The device 182 is connected to the selector valve 174 by the duct 34 to control the discharge of carbon dioxide into the hazard C. The duct 29 of the device 182 is connected to the branch 178 of the vapor header 175 and the duct 41 of the device is connected to the shuttle valve 184a. When a fire is discovered in hazard C, the device 182 is actuated by opening its actuating valve so that carbon dioxide vapors will immediately flow through the duct 41 to the shuttle valve 184a which is moved to close the duct 41 of the device 181 and permit the vapors to flow into the duct 189 to the shuttle valve 184 which is in turn moved to close the duct 41 of the device 179 and to permit the vapors to flow through the duct 185 to the pilot valve 171 in the branch duct 169. Admission of carbon dioxide vapors to the pilot valve 171 will cause the duct 169 to be opened and will eiiect opening of the master valve 168 to till the liquid carbon dioxide header 164 and each of its branches 165, 166 and 167.

After a predetermined time interval, during which the pilot valve assembly of the device 182 receives its charge of carbon dioxide vapor, the control valve of the device closes to eflect opening of the pilot valve so that vapor will flow through the duct 34 to open the selector valve 174 and permit carbon dioxide to be discharged into the hazard C. The discharge of carbon dioxide into the hazard C is continued for a suificient period of time to flood the hazard and is thereafter discontinued by movement of the pilot valve of the device 182 to its closed position to vent the duct 34 through the exhaust port of the pilot valve of the device. Resetting of the device 182 for subsequent operations is accomplished by returning the actuating valve to its closed position to vent the duct 41 and to reclose the master valve 168, as was previously described.

It will be readily apparent that the manner in which any one of the actuating and control devices 179, 181 and 182 is utilized to control operation of its selector valves 172, 173 or 174, respectively, may be varied to correspond with that of any one of the other devices and that various combinations may be employed. For example, a warning whistle, or the like, and a remote station might be used in connection with a single actuating and timing device.

It is to be understood that the forms of this invention herewith shown and described are to be taken as the preferred examples of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described the invention, we claim:

1. A fire extinguishing system, comprising a source of stored liquid carbon dioxide, a delivery pipe connecting said source to a point of use, a normally closed piston operated valve for said pipe, a duct for admitting carbon dioxide vapors from said source to the piston of said valve to open the latter, a pilot valve for said duct, pressure responsive means for operating said pilot valve to open said duct for a predetermined period of time, a second duct for admitting carbon dioxide vapors from said source to said pilot valve operating means, an actuating valve for said second duct, a control valve for said second duct, and pressure responsive means for operating said control valve to actuate said pilot valve operating means after said second duct has been open for a predetermined period of time.

2. A fire extinguishing system, comprising a source of stored liquid carbon dioxide, a delivery pipe connecting said source to a point of use, a normally closed piston operated valve for said pipe, a duct for admitting carbon dioxide vapors from said source to the piston of said valve to open the latter, a pilot valve for opening and closing said duct to open and close, respectively, said piston operated valve, operating means responsive to the admission of a charge of pressure fluid thereto and the subsequent stopping of said admission to move said pilot valve to its open position until a substantial portion of said charge has been released from the operating means, a second duct for admitting carbon dioxide vapors from said source to said operating means, an actuating valve for opening and closing said second duct, a control valve for opening and closing said second duct, pressure responsive means for opening said control valve when said actuating valve is opened and for closing said control valve after said actuating valve has been opened for a predetermined period, closing of said control valve effecting opening of said pilot valve, and means for releasing a susbtantial portion of the charge from said operating means at a retarded rate to close said pilot valve after it has been open for a predetermined period.

3. A fire extinguishing system, comprising a source of stored liquid carbon dioxide, a delivery pipe connecting said source to a point of use, a normally closed piston operated valve for said pipe, a duct for admitting carbon dioxide vapors from said source to the piston of said valve to open the latter, a pilot valve for said duct, pressure responsive means for operating said pilot valve to open said duct when a charge of pressure fluid has been admitted to the operating means and the admission of fluid has been stopped and to close said duct after a predetermined period of time during which pressure fluid is vented from the operating means at a controlled rate, a second duct for admitting carbon dioxide vapors from said source to said pilot valve operating means, an actuating valve for said second duct, a control valve for said second duct, and pressure repsonsive means for operating said control valve to open said second duct and admit a charge of carbon dioxide to said pilot valve operating means when said actuating valve is opened and to close said second duct and actuate said pilot valve operating means after said actuating valve has been open for a predetermined period of time during which an operating charge of carbon dioxide is admitted to said control valve operating means at a controlled rate.

4. A fire extinguishing system, comprising a source of stored liquid carbon dioxide, 21 delivery pipe connecting said source to a point of use, a normally closed piston operated valve for said pipe, a duct for admitting carbon dioxide vapors from said source to the piston of said valve to open the latter, a pilot valve for opening and closing said duct to open and close, respectively, said piston operated valve, valve operating means responsive to the introduction of a charge of pressure fluid thereto for opening said pilot valve after the introduction of the charge has been stopped, a second duct for admitting a charge of carbon dioxide vapors from said source to said operating means, a normally closed actuating valve for said second duct, a control valve for said second duct, means operative upon the opening of said actuating valve for admitting a charge of carbon dioxide vapors to said control valve at a retarded rate to close the control 13 valve and efifect opening of the pilot valverafter the actuating valve has been open for a predetermined time interval, and means for releasing the charge from said operating means at a retarded rate to cause the latter to reclose the pilot valve after it has been open for a predetermined period.

5. A fire extinguishing system, comprising a source of stored liquid carbon dioxide, a delivery pipe connecting said source to a point of use, a normally closed piston operated valve for said pipe, a duct for admitting carbon dioxide vapors from said source to the piston of said valve to open the latter, a plunger operated pilot valve for opening and closing said duct to open and close, respectively, said piston operated valve, said pilot valve having a chamber therein, a partition dividing said chamber into inner and outer portions and movable by a decrease in the pressure in the inner portion relative to the pressure in the outer portion to cause the plunger to open said pilot valve, a second duct for admitting carbon dioxide vapors from said source to the inner portion of said chamber, a passageway between the inner and outer portions of said chamber, a valve in said passageway permitting the unidirectional flow of carbon dioxide vapors from the inner to the outer portion of the chamber to equalize the pressures in both portions while carbon dioxide vapors are admitted through said second duct, said chamber having a vent opening from said inner portion and a restricted vent opening from said outer portion for decreasing the pressure in the inner portion relative to the pressure in said outer portion for a predetermined period of time after the admission of carbon dioxide vapors is stopped, an actuating valve in said second duct, a control valve in said second duct, and pressure responsive means for opening said control valve when said actuating valve is opened to admit carbon dioxide vapors to said chamber and for closing said control valve after a predetermined period of time to cause said partition to move said plunger and open the pilot valve.

6. A fire extinguishing system, comprising a source of stored liquid carbon dioxide, a delivery pipe connecting said source to a point of use, a normally closed piston operated valve for said pipe, a duct for admitting carbon dioxide vapors from said source to the piston of said valve to open the latter, a plunger operated pilot valve for opening and closing said duct to open and close, respectively, said piston operated valve, said pilot valve having a chamber therein, a partition dividing said chamber into inner and outer portions and movable by a decrease in the pressure in the inner portion relative to the pressure in the outer portion to cause the plunger to open said pilot valve, a second duct for admitting carbon dioxide vapors from said source to the inner portion of said chamber, a passageway between the inner and outer portions of said chamber, a valve in said passageway permitting the unidirectional flow of carbon dioxide from the inner to the outer portion of the chamber to equalize the pressures in both portions while carbon dioxide vapors are admitted through said second duct, said chamber having a vent opening from said inner portion and a restricted vent opening from said outer portion for decreasing the pressure in the inner portion relative to the pressure in said outer portion for a predetermined period of time after the admission of carbon dioxide vapors is stopped, an actuating valve in said second duct, a plunger operated control valve in said second duct having a chamber therein, a partition dividing said control valve chamber into inner and outer portions and movable in accordance with the relative values of the pressures in said inner and outer portions to cause the plunger of the control valve to open and close the latter, opening of said actuating valve admitting carbon dioxide vapors from said source to the inner portion of said control valve chamber to open the control valve and admit carbon dioxide vapors to the inner portion of the pilot valve chamber, and a passageway between said second duct and the outer portion of the control valve chamber for the controlled admission of carbon dioxide vapors to the outer portion of the control valve chamber to cause the plunger of the control valve to close the latter after said actuating valve has been open for a predetermined period or time, the closing of said control valve stopping the admission of carbon dioxide vapors to the inner portion of the pilot valve chamber to cause the pilot valve to be opened.

7. In a fire extinguishing system, the combination with a source of stored liquid carbon dioxide, a pipe for delivering liquid carbon dioxide from said source to a point of use, a normally closed piston operated valve for said pipe, and a pilot valve for admitting carbon dioxide vapors from said source to the piston of the valve for said pipe to open the valve, of pressure responsive valve operating means for opening said pilot valve to open said piston operated valve for a predetermined period of time after a charge of pressure fluid is admitted to the operating means and the admission of the charge has been stopped, a duct for admitting carbon dioxide vapors from said source to said valve operating means, an actuating valve for opening and closing said duct, a control valve for said duct, and pressure responsive means for opening said control valve when said actuating valve is opened to admit carbon dioxide vapors from said source to said valve operating means and for closing said control valve after said actuating valve has been open for a predetermined period of time to stop the admission of carbon dioxide vapors to the valve operating means.

8. In a fire extinguishing system, the combination with a source of stored liquid carbon dioxide, a pipe for delivering liquid carbon dioxide from said source to a point of use, a normally closed piston operated valve for said pipe, and a pilot valve for admitting carbon dioxide vapors from said source to the piston of the valve for said pipe to open the valve, of pressure responsive valve operating means for opening said pilot valve to open said piston operated valve for a predetermined period of time after a charge of pressure fluid is admitted to the operating means and the admission of the charge has been stopped, a duct for admitting carbon dioxide vapors from said source to said valve operating means, an actuating valve for said duct movable between an open position for opening said duct and a closed position for closing said duct and for venting the portion of said duct that is downstream from the actuating valve, and pressure responsive means for opening said control valve When said actuating valve is opened to admit carbon dioxide vapors from said source to said valve operating means and for closing said control valve after said actuating valve has been open for a predetermined period of time to stop the admission of carbon dioxide vapors to the valve operating means, movement of said actuating valve to its closed position causing the downstream portion of the duct to be vented for resetting the pressure responsive means for subsequent operation.

9. In a fire extinguishing system, the combination with a source of stored liquid carbon dioxide, a pipe for delivering liquid carbon dioxide from said source to a point of use, a normally closed piston operated valve for said pipe, and a pilot valve for admitting carbon dioxide vapors from said source to the piston of the valve for said pipe to open the valve, of pressure responsive valve operating means for opening said pilot valve to open said piston operated valve for a predetermined period of time after a charge of pressure fiuid is ad mitted to the operating means and the admission of the charge has been stopped, a duct for admitting carbon dioxide vapors from said source to said valve operating means, said duct having two parallel branches in one portion thereof, an actuating valve positioned adjacent said point of use for opening and closing one branch of said duct, a second actuating valve positioned at a point remote from said point of use for opening and closing the other branch of said duct, a control valve for the portion of said duct between its branched portions and said valve operating means, and pressure responsive means for opening said control valve when one of said actuating valves is opened to admit carbon dioxide vapors to said valve operating means and for closing said control valve after the actuating valve has been open for a predetermined period of time to stop the admission of carbon dioxide vapors to the valve operating means.

10. In a fire extinguishing system, the combination with a source of stored liquid carbon dioxide, a pipe for delivering liquid carbon dioxide from said source to a point of use, a normally closed piston operated valve for said pipe, and a pilot valve for admitting carbon dioxide vapors from said source to the piston of the valve for said pipe to open the valve, of pressure responsive valve operating means for opening said pilot valve to open said piston operated valve for a predetermined period of time after a charge of pressure fluid is admitted to the operating means and the admission of the charge has been stopped, a duct for admitting carbon dioxide vapors from said source to said valve operating means, an actuating valve for opening and closing said duct, a control valve for said duct, pressure responsive means for opening said control valve when said actuating valve is opened to admit carbon dioxide vapors from said source to said valve operating means and for closing said control valve after said actuating valve has been open for a predetermined period of time to stop the admission of carbon dioxide vapors to the valve operating means, and pressure fluid operated signal means in communication with said duct on the downstream side of said actuating valve for producing an alarm signal when said actuating valve is opened.

11. In a fire extinguishing system, the combination with a source of stored liquid carbon dioxide, a delivery pipe system therefor having a liquid carbon dioxide header with a branch extending to a point of use, a normally closed piston operated selector valve for said branch, a first pilot valve for admitting carbon dioxide vapors from said source to the piston to open the valve, a normally closed piston operated master valve for controlling the admission of liquid carbon dioxide from said source into said header, and a second pilot valve for admitting liquid carbon dioxide from said header to the master valve piston to open the master valve, of

pressure responsive valve operating means for opening said first pilot valve to open the selector valve for a predetermined period of time after a charge of pressure fluid is admitted to the operating means and the admission of the charge has been stopped, a duct for admitting carbon dioxide vapors from said source to said valve operating means, an actuating valve for opening and closing said duct, a control valve for said duct, pressure responsive means for opening said control valve when said actuating valve is opened to admit carbon dioxide vapors from said source to said valve operating means and for closing said control valve after said actuating valve has been open for a predetermined period of time to stop the admission of carbon dioxide to the valve operating means, and a second duct connecting the first duct on the downstream side of said actuating valve to said second pilot valve to open the latter and to effect opening of said master valve when the actuating valve is opened.

12. In a fire extinguishing system, the combination with a source of stored liquid carbon dioxide, a delivery pipe system therefor having a liquid carbon dioxide header with branches extending to different points of use, a normally closed piston operated selector valve for each of said. branches, each of said selector valves including a pilot valve for admitting carbon dioxide vapors from said source to. the piston to. open the valve, a normally closed piston operated master valve for controlling the admission of liquid carbon dioxide from said source to said header, and a pilot valve for. admitting liquid carbon dioxide from said header to the. master valve piston to open the master valve, of separate pressure responsive valve operating means for opening each selector pilot valve to open the associated selector valve for a predetermined period of time after a charge of pressure fluid is admitted to. the valve operating means and the admission of the charge has been; stopped, a duct having separate branches for admitting. carbon dioxide vapors from said source to each valve operating means, an actuating valve for opening and closing each branch of said duct, a control valve for each branch of said duct, pressure responsive means associated with each control valve for opening, the latter when the actuating valve for its branch duct. is,

pilot valve associated with said master valve to open.

the latter when the actuating valve is opened.

13. A device for controlling the actuation ofa pressure fluid operate-d valve, comprising a pressure fluid supply duct, a pilot valve for said duct, pressure. responsive means for operating said pilot valve to open said;

duct for a predetermined period of time after a charge of pressure fluid is admitted thereto and until a substantial portion of the charge has. been vented therefrom, a second duct for admitting pressure fluid tosaid pilot valve operating means, an actuating valve for open.- ing and closing said second duct, a control valve for opening and closing said second duct, and pressure responsive means for opening said control valve when said actuating valve is opened to admit a charge of pressure fluid to said pilot valve operating. means and for closing said control valve after said actuating valve has been open for a predetermined period of time to permit said charge to be vented from said pilot valve operating means.

14. A device for controlling the actuation of a pressure fluid operated valve, comprising a pressure fluid supply duct, a pilot valve for said duct, pressure responsive means for operating said pilot valve to open said duct after a charge of pressure fluid. is admitted thereto and the admission of said charge has been. stopped, means for venting a substantial portion of said charge from said pilot valve operating means at a retarded rate to close said pilot valve after it has been open for a predetermined period of time, a second duct for admitting pressure fluid to said pilot valve operating means, an actuating valve for opening and closing said second duct, a control valve for opening and closing said second duct, and pressure responsive means for opening said control valve when said actuating valve is opened to admit a charge of pressure fluid to said pilot valve operating means and for closing said control valve after said actuating valve has been open for a predetermined period of time during which said. charge. of pressure fluid is admitted to said pilot valve. operating means.

15. A device for controlling the actuation of a pres-- sure fiuid operated valve, comprising a pressure fluid supply duct, a pilot valve for said duct, pressure responsive means for operating said pilot valve to open said. duct after a charge of pressure fluid is admitted. thereto and the admission of said charge has been stopped, means for venting a substantial portion of said charge from said pilot valve operating means at a retarded rate to close said pilot valve after it has been open for 17 18 a predetermined period of time, a second duct for admitsaid actuating valve has been open for a predetermined ting pressure fluid to said pilot valve operating means, period of time during which said charge of pressure fluid an actuating valve for opening and closing said second is admitted to said pilot valve operating means. duct, pressure responsive control valve operating means for opening said control valve when said actuating valve 5 References Cted m the file of thls Patent is opened to admit said charge of pressure fluid to said UNITED STATES PATENTS pilot valve operating means, and means for introducing 2 307 784 Mapes Jam 12 1943 a charge of pressure fluid to said control valve operating 2:309:106 Doxsey et Jam 1943 means at a retarded rate to close said control valve after 2.356390 Getz Aug. 29, 1944 

1. A FIRE EXTINGUISHING SYSTEM, COMPRISING A SOURCE OF STORED LIQUID CARBON DIOXIDE, A DELIVERY PIPE CONNECTING SAID SOURCE TO A POINT OF USE, A NORMALLY CLOSED PISTON OPERATED VALVE FOR SAID PIPE, A DUCT FOR ADMITTING CARBON DIOXIDE VAPORS FROM SAID SOURCE TO THE PISTON OF SAID VALVE TO OPEN THE LATTER, A PILOT VALVE FOR SAID DUCT, PRESSURE RESPONSIVE MEANS FOR OPERATING SAID PILOT VALVE TO 